Particleboard made from remediated CCA-treated wood : evaluation of panel properties
Particleboard made from remediated CCA-treated wood : evaluation of panel properties
复制标题
由经过修复的 CCA 处理木材制成的刨花板：面板性能评估
作者：
C. Clausen;S. Kartal;J. Muehl
CCA处理的南方黄松（SYP）芯片修复单独利用酸提取，并使用酸提取，然后与金属耐受细菌地衣芽孢杆菌CC01的生物浸出。用10%脲醛树脂（UF）制备刨花板，测定了刨花板的内结合强度（IB）、弹性模量（莫伊）、断裂模量（莫尔）、厚度膨胀率（TS）、吸水率和耐腐性。与用未经处理的SYP碎片制备的PB相比，用仅酸提取的碎片和两步补救的碎片制备的PB板显示出IB分别平均降低22%和28%，莫尔分别降低41%和13%。与未处理的切片PB相比，酸提取的切片PB和补救的切片PB中的莫伊增加了8%至10%，这表明纤维表面已经发生致密化。吸水率和TS后24小时的浸没增加，在PB制备酸提取和补救芯片（14%至15%）。与未处理的芯片PB相比，酸提取的芯片PB的吸水率和TS更低（分别为28%和39%）。耐腐性是可变的，所有暴露于Postia胎盘的PB样品的重量损失较低（≤5%），暴露于密粘褶菌的未处理和补救PB的重量损失范围为11%至25%。我们的结论是，减少莫尔和IB看到在补救PB残留草酸脆化纤维或干扰UF树脂粘附的结果。结果ofthis研究表明，补救PB的属性减少时，CCA处理芯片暴露于草酸，即使在低酸浓度有限的时间。
CCA-treated southern yellow pine (SYP) chips were remediated utilizing acid extraction alone, and using acid extraction followed by bioleaching with the metal-tolerant bacterium Bacillus licheniformis CC01. Cleaned chips were used to make particleboard (PB) with 10 percent urea-formaldehyde (UF) resin, and the PB samples were evaluated for internal bond (IB), modulus of elasticity (MOE), modulus of rupture (MOR), thickness swell (TS), water absorption, and decay resistance. PB panels prepared from just acid-extracted chips and two-step remediated chips showed an average 22 and 28 percent reduction, respectively, in IB and 41 and 13 percent reduction, respectively, in MOR compared to values for PB prepared with untreated SYP chips. An 8 to 10 percent increase in MOE in the acid-extracted-chip PB and remediated-chip PB compared to the untreated-chip PB suggested densification of the fiber surface had occurred. Water absorption and TS after 24-hour submersion increased in PB prepared from acid-extracted and remediated chips (14% to 15%). Water absorption and TS were less (28% and 39%, respectively) for the acid-extracted-chip PB compared to the untreated-chip PB. Decay resistance was variable, with low weight losses (≤5%) for all PB samples exposed to Postia placenta and weight losses ranging from 11 to 25 percent for untreated and remediated PB exposed to Gloeophyllum trabeum. We conclude that reduced MOR and IB seen in remediated PB are the result of residual oxalic acid either embrittling the fiber or interfering with UF resin adhesion. Results ofthis study indicate that properties of remediated PB are diminished when CCA-treated chips are exposed to oxalic acid even at low acid concentrations for limited amounts of time.